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It is shown that in an optically thick medium, the extremely relativistic electrons in the Maxwellian distribution will generate in a magnetic field low frequency synchrotron radiation with the Rayleigh-Jeans spectrum. Based on the Fokker-Plank equation, the fast electrons accelerated by this kind of wave field will have a power-law energy spectrum. Considering the physical conditions of the coronal active regions, the observed electron spectra at about 10 Mev in solar flares are probably due to the acceleration of fast electrons by the synchrotron radiation.

The discrepancy on the coronal magnetic field between solar optics and radio is analysed by using magnetic fibril concept with filling factor and fractal structure model. The magnetic field of about 100 G considered in solar optics is the mean value in a large scale, and that of about 1000 G in solar radio should be the value of fine structures inside macro loop.

We analytically study the turbulent acceleration of solar protons by strong Langmuir plasmons in Cerenkov processes. It is shown that among the wave spectra with self-retained source only the Pelletier spectrum (Wk∝k-7/2) can result in the energy spectrum of non-relativistic protons, which gives a good fit to that observed from solar flare events. It is quite possible that strong Langmuir turbulence presents in coronal active region, with three-dimensional, isotropic and stationary spectrum proportional to k-7/2, and is responsible for the acceleration of flare protons.

Because late-type stellar wind has low temperature, massive outflow, and high terminal velocity, theoretical models of thermal pressure or radiation pressure cannot explain the acceleration of late-type stellar wind. Energy damping of Alfven wave in stellar winds is small, and Alfven wave is perhaps the driving force of late-type stellar wind if the wave energy-flux is large enough. After theoretical analysis and numerical calculation, we get various velocity distributions by taking various wave energy-fluxes in reliable range, the terminal velocities accord with observations. If late-type stellar winds are driven by thermal pressure, the temperature is higher than acceptable. The results of Alfven wave driving winds also indicate that massive stellar winds need large energy flux and acceleration is closely related with gravity. In discussion we think that Alfven wave accelerating late-type stellar wind is feasible and the initial energy-flux, damping of Alfven wave in stellar winds need further study.

This paper analytically investigates the nonlinear behaviour of transverse plasmons in pair plasmas on the basis of the nonlinear governing equations obtained from Vlasov—Maxwell equations. It shows that high frequency transverse plasmons are modulationally unstable with respect to the uniform state of the pair plasma. Such an instability would cause wave field collapse into a localized region. During the collapse process, ponderomotive expulsion is greatly enhanced for the increase of wave field strength, leading to the formation of localized density cavitons which are significant for the future experimental research in the interaction between high frequency electromagnetic waves and pair plasmas.

Using the two fluid model, the problem of two-dimensional steady-state magnetic reconnection in incompressible resistive weakly ionized plasmas is analysed. Under the strong-coupling condition such as in the Sun's photosphere, it allows us to express the current sheet analytically. In this case the current sheet scales as η1/2. Then this model is used to understand magnetic flux cancellation which is observed in the Sun's magnetograms. To account for a cancelling flux of 1×1018 Max in a time interval of 77 min, the width of the current sheet is about ten kilometres.

In a binary system of a background fluid-wave field, the wave effect may be important in some cases. From general properties of thermodynamics of the medium, we derive the coupling equations for the mean flow-wave field. For six wave modes (Langmuir wave, ion-acoustic oscillations, whistlers, Alfven waves, magneto-acoustic oscillations, and transverse plasma wave) the corresponding representation of the wave stress tensor is found. Finally, the representation for the Alfven waves is applied to the faculae heating and a result consistent with observations is obtained.

Active regions in celestial bodies are usually accompanied by the presence of plasma turbulence and scattering by this turbulence must greatly alter the spectral characteristics of the radiation produced. The large spectral index usually observed in cosmic X-rays is difficult to explain by the usual Compton (or synchrotron) mechanism. In this paper, we investigate specifically the effect of scattering by plasma turbulence on the Compton process and obtain an X-ray spectrum in agreement with the observed spectrum.

We suggest that quasi-stationary, high-frequency Langmuir turbulence may exist in active regions of the solar corona and that it is this turbulence that causes the enhanced radio emission in the meter wave bands. We discuss the acceleration process by the turbulence and some observations.

Radiation and energy loss by monopole in cosmic plasma are investigated in detail. The general formulae for monopole radiation are derived; the Cerenkov power and spectra radiation differing from ones of charged particles are found; and its energy loss in cosmic plasma and metal is obtained. It is pointed out that it is possible to examine monopole in virtue of the Cerenkov radiation in ordinary medium.

It is well known that under cosmic conditions the various modes of plasma turbulence waves (including MHD waves) are easily excited. In this paper we are trying to show that the turbulent wave also generates a source-term for the magnetic induced equations as does the turbulent fluid with nonzero helicity. By expanding the turbulent field in Fourier series, we have obtained dynamo equation for turbulent wave and a reasonable solution which indicates that the poloidal field may be built-up in the turbulent source region. Perhaps, we may think that the poloidal field of Equation (9) is the analytical form of the magnetic field in a turbulent source region of celestial bodies.

The steep temperature distribution with height in the solar chromosphere-corona transition zone is one of the unsolved problems in solar physics. This paper presents a qualitative and quantitative explanation to this steep distribution of temperature in terms of the pileup effect of the oscillations in a plasma and the mechanism of wave-particles nonresonant heating. Analysis shows that if a proton beam of high energy is continuously injected into the transition zone from the chromosphere, the steep distribution of temperature is able to appear in a narrow layer through the plasma wave-particles nonlinear interactions.

It is shown that curvature radiation of magnetic monopole is suppressed in a plasma medium.

We investigate the possibility of an additional acceleration of the high speed solar wind by whistler waves propagating outward from a coronal hole. We consider a stationary, spherically symmetric model and assume a radial wind flow as well as a radial magnetic field. The energy equation consists of (a) energy transfer of the electron beam which excites the whistler waves, and (b) energy transfer of the whistler waves described by conservation of wave action density. The momentum conservation equation includes the momentum transfer of two gases (a thermal gas and an electron beam). The variation of the temperature is described by a polytropic law. The variation of solar wind velocity with the radial distance is calculated for different values of energy density of the whistler waves. It is shown that the acceleration of high speed solar wind in the coronal hole due to the whistler waves is very important. We have calculated that the solar wind velocity at the earth's orbit is about equal to 670 km/sec (for wave energy density about 10−4 erg cm−3 at 1.1R⊙). It is in approximate agreement with the observed values.